Stable tar-in-water dispersions and method for preparing same



I Patented Feb. 21,1961

STABLE TAR-IN-WATER DISPERSIGNS AND METHOD FGR PREPARENG SAME Louis Cohen, Cleveland, Ohio, assignor to The B. F. Goodrich Company, New York, N.Y., a corporation of New York No Drawing. Filed Mar. 9, 195d, Ser. No. 797,880

12 Claims. (Cl. 260-114) This invention relates to stable tar-in-water emulsions or dispersions and more particularly pertains to compositions comprising dispersions of finely-divided tar particles in water and to the method for preparing said compositions.

This invention is concerned with novel emulsions or dispersions in which tar is the dispersed phase and water is the continuous phase said emulsions or dispersions having unusual resistance to creaming or settling and to coalescence or coagulation of the dispersed phase.

The tar embodied in the present invention is the liquid, semi-liquid or solid thick brown to black substance with a distinctive odor obtained by the distillation of wood, peat, coal and other vegetable matter. The most commonly used tars of the type embodied in this invention are those known as coal tar and Wood tar. These tars are to be distinguished from the petroleum based asphalts. The preferred tars for the purpose of this invention are the road tars, known as RT, in the viscosity range of RT-l to RT-l2, inclusive.

Tar is an excellent material for use in the building trade and in road and airport runway surfacing. Tar has an advantage which asphalt does not have, namely, insolubility or inertness to gasoline, kerosene and petroleum oils in general. This advantage is a real one, especially in the road surfacing industry where accidentally spilled fuels and oils can cause serious damage to many types of road surfaces. Tar has been applied to road surfaces in the molten state. This is generally undesirable. Tar dispersions suitable for use in the building and the road construction and maintenance trades have not been available heretofore because of the hydrophobic nature of tar and the lack of natural emulsifying and dispersing agents in tar. Tar-in-water dispersions which have been prepared and used prior to my invention have contained relatively large amounts of emulsification agents of the fatty acid and lignin types and hydrophilic fillers such as clay. They have been relatively unstable to aging, and films formed from the tar dispersions of the prior art exhibit inferior physical properties and in particular a high degree of watersensitivity by virtue of the residual emulsification agents and hydrophilic fillers present in said films. The prior art tar dispersions have not exhibited the proper stability, that is, many of them tend to cream or settle upon standing, so that an agitation or homogenization step is required prior to and even during their application to a surface. The tar-in-water dispersions of this invention can be deposited or coated at moderate temperatures on surfaces to form continuous tar films which are of low water sensitivity. Such dispersions can be applied to roads, for example, to provide surfaces impervious to gasoline, petroleum oils and greases of the types which occasionally drip from or are accidentally spilled from motor vehicles. Such surfaces are also unaifected by atmospheric moisture or natural precipitation.

Accordingly, an object of the present invention is the provision of tar-in-water dispersions which can be prepared with or without extraneous fillers and which reings and deposits of tar upon the evaporation of the Water phase said coatings and deposits exhibiting a negligible degree of water-sensitivity. Another object is the provision of a method for preparing said stable tar-inwater dispersions.

Still further objects and advantages of the present invention will appear from the more detailed description and examples set forth below, it being understood that such detailed description is given by way of illustration and explanation only, and not by Way of limitation, since various changes therein may be made by those skilled in the art without departing from the scope and spirit of the invention.

1 have discovered a novel stable composition comprising at least 35 parts by weight of water, up to about 65 parts by Weight of finely dispersed tar and a minor proportion of a synthetic, lightly cross-linked, waterswellable, carboxyl containing polymer and sufiicient neutralizing agent to impart a pH of from about 5 to about 8. I

The tar-in-water dispersions embodied in the present invention can be prepared by homogenizing in any desired order the aforementioned tar, synthetic, lightly cross-linked, Water-swellable, carboxyl containing polymer, neutralizing agent and Water.

The synthetic, lightly cross-linked, water-swellable, carboxyl containing polymers embodied in this invention are useful in the range of from 0.05 to 2% by weight and, preferably, from 0.06 to 1.5% by Weight based on the weight of tar. These polymers include interpolymers of at least 20% by weight of an alpha, betaolefinically unsaturated carboxylic acid or anhydride thereof, up to about by weight of another monoolefinic monomer copolymerizable therewith and from about 0.01 to about 10% and more preferably 0.01 to about 5% by weight based on the total weight of monomers of an olefinic monomer having at least two polymerizable olefinic groups in each molecule. It is to be understood that in the above proportions, if a maximum amount of two of the monomers are utilized that somewhat less than maximum amounts of the other monomers must be utilized.

It is to be understood also that the Water-swellable carboxyl containing polymers can be composed of only two essential ingredients, the polymerizable acid and a ,cross-linking ingredient, which is the olefinic monomer having at least two polymerizable olefinic groups in each molecule.

In the alpha, beta-olefinically unsaturated acids the.

close proximity of the strongly polar carboxyl group or carboxylic anhydride group to the double bonded carbon atoms has a strong activating influence rendering the substances containing this structure very readily polyboxylic acids include maleic acid, fumaric acid, citraconic acid, mesaconic acid, glutaconic acid or anhydrides thereof and halogen substituted derivatives of these acids or anhydrides.

Representative polyolefinically unsaturated monocar- :boxylic acids are 'pentadiene-Zficic acid, sorbic acid, an

9 Q hyrides thereof and halogen substituted derivatives.

The preferred alpha, beta-olefinically unsaturated car- I boxylic acids for use in this invention are the monoolefinic acrylic acids having the structure i CHz=CCOOH because of its generally lower cost, ready availability,

and ability to form superior polymers.

The swelling capacity (or swelling index) of'the lightly cross-linked interpolymers depends primarily upon the carboxyl groups in the interpolymer chain, therefore, it is generally desirable to utilize as much of the carboxylic monomer or monomers and as little of the other monomeric constituents as is consistent with the necessary water sensitivity, dispersibility, emulsification,suspension, thickening and other desirable properties. In these interpolymers the carboxylic monomer or monomers should never be less than 20% by weight of the total monomeric mixture.

Additional monomers suitable for the production of multi-component interpolymers, as above described, are monoolefinic monomers such as the fluoro-, chloro-, bromo-, iodoand ethoxy styrenes, nuclear sulfonated styrenes, acrylamide, methacrylamide, N,N-dimethyl acrylamide, N-methyl methacrylamide, acrylonitrile, methacrylonitrile, vinylidene cyanide, methyl acrylate, ethyl acrylate, propyl acrylates, butyl acrylates, amyl acrylates, hexyl acrylates, cyclohexyl acrylate, heptyl' acrylates, octyl acrylates, methyl methacrylate, methyl ethacrylate, vinyl acetate, vinyl propionate, vinyl butyrate, isopropenyl acetate, isopropenyl propionate, isopropenyl butyrate, vinyl benzoate, isopropenyl benzoate, vinyl pyridines, vinyl chloride, vinyl bromide, vinyl fluoride, vinylidene chloride, vinylidene bromide, vinylidene fluoride, vinylidene chlorobromide, vinyl carbazole, vinyl pyrrolidone, vinyl piperidines, vinyl pyrimidines, methyl vinyl ketone, ethyl vinyl ketone, methyl isopropenyl ketone, ethylene, propylene, dimethyl maleate, diethyl maleate, dimethyl fumarate, diethyl fumarate, methyl vinyl ether, ethyl vinyl ether, the propyl vinyl ethers, the butyl vinyl ethers, cyclohexyl vinyl ether, phenyl vinyl ether, allyl acetate, allyl propionate, allyl benzoate, isobutylene, and other monomeric substances which are copolymerizable with the alpha, beta-olefinically unsaturated carboxylic acid. Of the above additional monomers N-methyl acrylamide, acrylonitrile, methyl vinyl ether, vinyl acetate, isobutylene and styrene have been found particularly useful for the production of waterswellable interpolymers Interpolymers can be made from mixtures of maleic anhydride, 2. vinyl alkyl ether such as methyl vinyl ether, and a cross-linking agent as herein defined in which the sum' of the moles of vinyl ether is substantially equivalent to the molar quantity of maleic anhydride present.

The cross-linking agents useful in the practice of this invention are olefinic monomers having at least two polymerizable olefinic groups per molecule. The cross-linking agents embodied in this invention include such compounds as divinyl benzene, nuclear substituted divinyl benzenes, di-isopropenyl benzene, trivinyl benzene, nuclear substituted trivinyl benzenes, triisopropenyl benzene, triallyl benzene, 1,6-heptadiene and similar termi nally olefinically unsaturated non-conjugated dienes of the type disclosed in the copending U.S. patent application Serial No. 737,541, filed May 26, 1 958 by John F. Jones, Alfred J. Mital and Franz A. Regenass, tetravinyl silane, tetraallyl silane, and similar polyalkenyl monomegs disclosed in the copending U.S. patent application of John F. I ones and Alfred J. Mital, Serial No. 701,328, filed December 9, 1957, triacrylyl triazine, trimethacrylyl triazine, methylene-bis-acrylamide, methylene-bis-methacrylamide, hexaallyl trimethylene trisulfone, squalene, myrcene, alkali metal polymerized 1,2-polybutadiene, alkali metal polymerized 1,2- and 3,4-polyisoprene, divinyl spirobi, polyalkenyl polyethers of the type disclosed in U.S. Patent No. 2,789,053, and the like and others.

In addition to the foregoing cross-linking agents other suitable cross-linking agents which contain hydrolyzable linkages can be employed in the production of tar-inwater dispersions in applications where long-term stability is not essential. Such hydrolyzable cross-linking agents include allyl acrylate, methallyl acrylate, crotyl acrylate, and others disclosed in U.S. Patent No. 2,340,111.

The preferred cross-linking agents are the polyalkenyl polyethers, the polyalkenyl silanes and the terminally olefinically unsaturated dienes.

The preferred method of preparation of the waterswellaole carboxyl containing polymers embodied in this invention is polymerization in an inert diluent having some solubilizing action on one or more of the monomeric ingredients but substantially none on the resultant interpolymer. Polymerization in mass may be employed, but is not preferred because of the difficulty in working up the solid polymeric masses obtained. Polymerization in an aqueous medium containing a water-soluble freeradical catalyst is useful, the product resulting either as a granular precipitate or as a highly swollen gel, either of which may be used directly or are easily further subdivided and dried. Polymerization in an organic liquid which is a solvent for the monomers but a non-solvent for the interpolymer, or in a mixture of such solvents, in the presence of a solvent-soluble free-radical catalyst such as benzoyl peroxide and azobisisobutyronitrile is most preferred because the product is usually obtained as a very fine friable and often fluffy precipitate which, after solvent removal, seldom requires grinding or other further treatment before use. Suitable solvents for the latter method include benzene, toluene, xylene, ethyl benzene, tetralin, hexane, heptane, octane, carbon tetrachloride, methyl chloride, ethyl chloride, ethylene dichloride, bromotrichloromethane, chlorobenzene, acetone, methyl ethyl ketone, and others, and mixtures of these and other inert solvents.

Polymerization in the diluent medium may be carried out in the presence of a free-radical catalyst in a closed vessel in an inert atmosphere and under autogenous pressure, artificially induced pressure or in an open vessel under reflux at atmospheric pressure. The temperature of the polymerization may be carried, from 0 C. or lower to 100 C. or higher, more preferably from 20 to C., depending to a large degreev upon the activity of the monomers and catalyst used and the molecular weight desired in the polymeric product. The molecular weights of said interpolymers are greater for those made in the lower temperature range than for those made in the higher temperature range. Polymerization at 50 to 90 under atmospheric pressure using a free-radical catalyst is generally effective in producing a polymer yield of 75 to of theory in less than 10 hours, usually in less than 5 hours. Suitable free-radical catalysts include peroxides such' as sodium, potassium and ammonium persulfates, caprylyl peroxide, benzoyl peroxide, pelargonyl peroxide, hydrogen peroxide, cumene hydroperoxide, tertiary butyl diperphthalate, tertiary butyl. perbenzoate, sodium peracetate, sodium percarbonate, and the like as well as azobisisobutyronitrile and others. Other catalysts utilizable are the so-called redox type of catalyst and the heavy-metal activated catalyst systems. lolymerization may be induced by radicalsformed in the polymerization system by nuclear radiation, X-rays and ultra-violet radiation.

The neutralizing agent employed in the present inven bonate, cesium bicarbonate and the like.

- tained by neutralizing from about 50 to about 80% of the carboxyl groups present in the polymer. The alkali metal hydroxide, oxide or carbonate forms the alkali metal salt of the carboxyl containing polymer and thus makes the polymer more water sensitive and highly swollen in water. t is believed that the basic organic amine functions to increase the swell of the carboxyl containing polymer and also to make the carboxyl containing polymer compatible with the dispersed tar phase.

The alkali metal hydroxides, oxides and carbonates useful in this invention include sodium hydroxide, sodium oxide, sodium carbonate, sodium bicarbonate, potas: sium hydroxide, potassium oxide, potassium carbonate, potassium bicarbonate, lithium hydroxide, lithium oxide, lithium carbonate, lithium bicarbonate, rubidium hydroxide, rubidium oxide, rubidium carbonate, rubidium bicarbonate, cesium hydroxide, cesium oxide, cesium car- The preferred of this group are the sodium and potassium hydroxides and carbonates.

The basic organic amines useful in this invention include the higher aliphatic primary, secondary, tertiary amines and quaternary amine hydroxides and alkylene oxide-treated amines. Specific examples of higher organic amines include n-octyl amine, di-n-octyl amine, trin-octyl amine, n-decyl amine, di-n-decyl amine, tri-n-decyl amine, n-dodecyl amine, di-n-dodecyl amine, tri-n-dodecyl amine, stearyl amine ethylene oxide treated dodecyl amine and tetraalkyl ammonium hydroxides such as tetraoctyl ammonium hydroxide and tetrado'decyl ammonium hydroxide. The preferred higher organic amines are dodecyl amine and the compound wherein x-l-y equals about 15, said compound having molecular weight of about 875.

The weight ratio of basic organic amine-to alkali metal hydroxide, oxide, or carbonate in the. aforementioned neutralizing agent can be from about 0.01251 1 to: about 0.2:1 respectively. J

The tar-in-water dispersions embodied in' this invention are most conveniently prepared by adding the acid form of the carboxyl containing polymer to water rnixing with a medium speed Waring Blendor or. similarmechanical mixer of the Lightnin and Eppenbach types followed by partial neutralization of the polymer to the desired pH with the neutralizing agent. The resulting inucilage is maintained at a temperature of from about 25 C. to about 100 C. whilemolten taris added'slowly, with continuous stirring, to the mucilageg The tar dispersion such blends are generally tough and'rubbery in nature. The addition of fillers to the tar dispersions generally results in the production of harder films deposited therefrom.

V tained at 55-70 C. and when the addition is completed,

-to creaming and coalescence on standing for long periods 'ofitime.

In the preferred method for the preparation of the tar dispersions embodied herein it is important that a relatively slow addition of the tar to the water phase be employed. Preferably, the tar addition is not any faster than the dispersion rate.

When highly viscous road tars (RT-9 to 12) are dis persed, it is preferred to mix the molten tar with a hot water phase wherein the temperature of the tar phase is maintained at 55130 C. and the water phase is mainthe mixing is stopped and the resulting homogeneous dispersion is cooled rapidly without further agitation. The less viscous road tars (RT-1 to 8) and the water phase may be mixed conveniently at normal temperatures.

In the preparation of the tar dispersions it is preferred that a sufiicient quantity of neutralizing agents be used in the water phase to impart a pH of from about 5.2 to 7 to the dispersion. Once the dispersion has been prepared the pH may be adjusted to pH value below 5.2 and above 7, if it is so desired, without noticeable efiect on the stability of the dispersion.

In the following illustrative examples the amounts of ingredients are given in parts by weight unless otherwise specified.

Example I the polymer. A sample of 300 parts of RT-12 grade tar of the type widely used in road construction was heated to 130 C. and added slowly to the above-described aqueous gel. The mixing of the aqueous gel and warm tar was conducted with a Waring Blendor at medium speed. The mixing was discontinued assoon as the addition of the tar was completed and the resulting dispersion was cooled to room temperature. dispersion of tar in water resulted which had fairly fine particle size and a pH of 6.8. The Brookfield viscosity of this 50% tar-in-water dispersion was 4150 centipoises. The,.tar-in-watendispersion .of this example was stable When unusually high speed mixing is employed during the addition of the warm tar or when the described Waring Blendor mixing is prolonged after the completion of theaddition of the tar, unstable dispersions result.

The stable dispersion described above was coated on 'Ta sheet of steel and was allowed to dry. A continuous can be used hot or it can be cooled and stored for long,

periods of time without creaming or coagulation. Generally the tar dispersions prepared with high shear mixing tend to be characterized by a fine particle size and are very smooth but dry more slowly when coated-on a surface than do the tar dispersions formed with slow speed mixing (Lightnin or Eppenbach mixers); The latter dispersions tend to be more grainy but the larger particle size allows fast and even drying of thick films. The tarin-water dispersions of this invention can be blended with aqueous dispersions of natural or synthetic rubbers, with natural or synthetic rubber latex or with dispersions and emulsions of synthetic plastics and films resulting from t'rernely sensitive to water.

film of "tar was observed on the surface of the steel and this tar film was substantially insensitive to water upon im' mersion in a water bath for 5 days.

Two 50% aqueous dispersions of RT-IZ were prepared in accordance with the teaching of US. Patent No. 2,670,- 332, one was prepared employing a Lightnin mixer and the other was prepared by means of a Waring Blendor. The dispersions were excellent in appearance immediately after preparation, but settling of the tar phase to a hard cake was observed in each after a weeks standing. In each case the tar cakes were so thick that it was difficult to push a spatula through them. The cakes could, however, be redispersed with a Lightnin mixer. from theseoriginal dispersions on steel plates were ex- Upon immersion of the coated plates in water for one day it was observed that the films absorbed :water and completely lost their adhesion to the A stable, pourable.

Films cast,

'5' plates. The foregoing experiments serve to distinguish the novel tar-in-water dispersions embodied in the instant invention from those of the prior art.

8 Example IV In a manner similar to that described in Example I a tar-in-water dispersion was made from a mixture of 348 Exam 18 H parts of distilled water, 0.875 part of an interpolymer of acrylic acid and 1.25% tetravinyl silane, 2.6 parts of The procedure described in Example I was followed aqueous sodium hydroxide, 0.44 part of the compound and the following ingredients were used to prepare the (CH CH O) 2 Z x following tar-in-water d1spers1ons:

10 CnHzs- A B c in tcnicnimwli wherein x+y= having a molecular weight of 875 Water-- 300 300 300 300 (Ethomeen C-25), and 287 parts of RT-12 tar. The i cii i rei p01 1 5 l 5 1 5 1 5 final dispersion had a Brookfield rpm.) viscosity of Poi hyieiigigsassassin-stagnant; i 15 640 cps. at C. The emulsion was stable in spite of e r h fi yign au i modified dodecylamine. 0 5 the fact that it had a relatively large particle size.

1; on"- -2'" 0.5 1.13 Quaternaig ar in e hydroxide (Arquad-O- Example V hydroxide, 55% sol. in Aleohol) 1.0 109350.11. hydroxide SOIL-biotin i5 A tar-in-water dispersion was prepared according to g (BT42) 3 g 3 g 2 g 2 g 20 the procedure outlined in Example I from a mixture of 342.1 parts of distilled water, 1.75 parts of an interpolymer of acrylic acid and 2.5% 1,8-n0nadiene, 5.25 parts of. 10% All of the above dispersions were good. Dispersion D aqueous sodium hydroxide solution, 0.88 part of Ethowas particularly good in that it was unusually smooth and meen (3-25 and 287 parts of RT-12 tar. An excellent of fine particle size. All of the above dispersions were 25 dispersion having good stability and a smooth consistency stable on aging. Dispersion B, for example, showed no and a Brookfield (20 r.p.m.) viscosity of 9,200 at 25 C. phase separation after aging for one month at 130 C. resulted. in a closed container. Example VI g; above'descnbefg iig form excellent i g A tar-in-water dispersion was prepared according to the 1 on h 1 ,5? g fi 5 rtoug the procedure given in Example I from a mixture of 318.5 Wk 13 g i a 93 f fi ypes parts of distilled water, 7.0 parts of an interpolymer of ere n par S G 6 ya y Sucrose acrylic acid and 0.2% tetraallyl silane, 21 parts of 10% Polymer were employed are'much {note Scans p t aqueous sodium hydroxide, 3.5 parts of Ethomeen C-25 flan be coated on porous surfaces with no penetration into and 287 parts of RT 12 tan An excellent easily Penn 6 pores E I III able dispersion resulted which had a Brookfield (20 6 1.p.m.) viscosity of 1,300 cps. at 25 c. This dispersion This example illustrates the use of fillers in the tar-inwas of a light brown color and formed smooth coatings Water dispersions of the present invention. A standard on paper. The dispersion had excellent stability to tar-in-water dispersion of the type D in Example II aging. was used in the present example. Each of the fillers 40 80 parts of the tar-in-water emulsion described above was added to the dispersion and mixing was accomplished were blended with 8 parts of a synthetic nitrile rubber with a Lightnin mechanical mixer. In each case 30% latex (an interpolymer of 55% butadiene and acryloby Weight of filler was used based on the weight of the nitrile) as follows. The rubber latex and tar emulsion tarpresent in the dispersion. A control dispersion (A) were compatible giving a greenish gray formulation havis included in this example. 4 ing fair fluidity capable of forming very smooth coatings A B O D Dispersion. 180 g 180-- 180 180.

a 1'- 21--. 27 27. Silica flour (100 mesh) 27 Talc (Asbestine 3X) 27 Dixie clay- 27. Dried films fairly soft, harder, smooth harder, smooth.- hard, somesmooth. what rough. Original dispersion properties:

Brookfield (20 r.p.m.) Vise eps. 15, R00 16, 250 3, 21,000. pH 6. 6. 8. 16 Days aging, dispersion properties:

Brookfield (2O r.p'.m.) Vise eps.. 23, 13,250 2, 7 12,500. mi 6. 6. 8. 6.6. Crust; on top slight no no no.

Films of the above-described dispersions were cast on aluminum panels. The final thickness of the dried films was about 0.041-0. 045 inch. The percent moisture pickup was determined for these films after air drying for 66 hours to constant weight followed by immersion in water for the indicated number of days.

, Percent Moisture Pickup 7 A B C D 1 day's imIrersiorL 1.78 4. 25 7 days immersion..- V 2.79 4.44 14 days immersion 3. 14 4. 64 2.53 5.13

tion which yields metallic appearing films upondrying. 1

These tar and aluminum-in-water dispersions are excellent for coating roofs and as insulation coatings in uil in cqnst us o an n pack n aaaaess 9 Example VII A tar-in-water dispersion was made by the procedure given in Example I from a mixture of 342.1 parts of distilled water, 1.75 parts of an interpolymer of acrylic acid and 1% tetraallyl pentaerythritol, 5.25 parts of a 10% aqueous sodium hydroxide solution, 0.88 part of Ethomeen C25 and 287 parts of RT-12 tar. The cooled dispersion had a viscosity of 23,000 cps. The dispersion was stable and smooth. I

In a similar manner a tar-in-water dispersion was prepared from the foreging ingredients except that a softer tar, RT8, was substituted for the RT-12. The resulting dispersion was very stable and smooth and it had a viscosity of 58,000 cps. at 25 C.

Example VIII A number of dispersions were prepared using the procedure described in Example I employing a copolymer of 99.5% acrylic acid and 0.5% tetraallyl pentaerythritol, Armeen C25, sodium hydroxide and RT-8. The tar phase and the water phase were both maintained at about 25 C. during the addition. The variations in method of preparation and properties of these dispersions are given in the following table.

Percent Percent Addition R Polymer pH Time, Mixer Dispersion minutes 53. 5 0.22 6.3. 4 Waring Blender.) Good. 50. 0.125 6.9 Lightnin Do. 50 0. 063 6.6 6 h Do. 50. 0. 125 6. 25 Excellent. 50. 0.125 9.0 3 No good. 63.6 0.091 6.27 19 Excellent.

Example IX A series of dispersions wasprepared as described in Example VIII with the exception that RT-12 was used. An addition time of 9 minutes and an Eppenbach mixer were used throughout. The results are listed in the following table.

I claim:

1. A stable tar-in-water dispersion comprising at least 35 parts by weight of water, up to about 65 parts by weight of homogeneously and finely dispersed coal tar and as the sole emulsifying and dispersing agent from 0.05 to about 2 parts by weight based on 100 parts of said coal tar of a mixed alkali metal base-organic amine salt of a synthetic lightly cross-linked water-swellable carboxyl containing polymer the weight ratio of the alkali metal base to organic amine being from about 0.0125 :1 to about 0.221 said alkali metal base being selected from the group consisting of alkali metal hydroxides, oxides and carbonates, said organic amine having at least 6 carbon atoms and being selected from the class consisting of aliphatic primary, secondary, tertiary amines, quaternary amine hydroxides and alkylene oxidetreated amines and said lightly cross-linked carboxyl containing polymer being an inter-polymer of (1) at least 20% by weight of an alpha, beta-olefinically unsaturated carboxylic acid, (2) up to about by weight of mo ther monoolefinic monomer copolymerizable with (1) and (3) from about 0.01 to about 10% by weight based on the total weight of monomer of an olefinic monomer having at least two polymerizable olefinic groups in each molecule said dispersion having a pH of from about 5 to about 8.

2. The dispersion of claim 1 wherein the coal tar is in the range RT-l to 12.

3. The dispersion of claim 1 wherein the synthetic lightly cross-linked Water-swellable carboxyl containing polymer is an interpolymer of from about to 99.99% by weight'of acrylic acid and from about 0.01%

to about 5% by weight of an olefinic monomer having at least two olefinic groups in each molecule.

4. A stable, tar-in-water dispersion comprising at least 35 parts by weight of water, up to 65 parts by Weight of homogeneously and finely-dispersed RT-l to 12 coal tar and as the sole emulsifying and dispersing agent from 0.05 to 2 parts by weight based on parts of said coal tar of a mixed alkali metal base-basic organic amine salt of an interpolymer of from about 95% to 99.99% by weight of acrylic acid and from about 0.01% to about 5% by weight of an olefinic monomer having at least two olefinic groups in each molecule said alkali metal base being selected from the group consisting of alkali metal hydroxides, oxides and carbonates and said organic amine having at least 6 carbon atoms the weight ratio of said base to said amine being from about 0.0125:1 to 0.221 respectively said dispersion having a pH of from about 5 to 8.

5. A stable tar-in-water dispersion comprising at least 35 parts by weight of water, up to 65 parts by weight of homogeneously and finely-dispersed RT-l to 12 coal tar and as the sole emulsifying and dispersing agent from 0.06 to 1.5 parts by weight based on 100 weight parts of said coal tar of a mixed sodium hydroxide-polyethylene oxide modified dodecyl amine salt of an interpolymer of from about 95% to 99.99% by weight of acrylic acid and from about 0.01% to 5% by weight of a polyallyl sucrose the Weight ratio of said hydroxide to said amine being from about 0.0125:1 to 0.2:1 respectively said dispersion having a pH of from about 5.2 to 7.

6. A stable tar-in-water dispersion comprising at least 35 parts by weight of water, up to 65 parts by weight of homogeneously and finely-dispersed RT-l to 12 coal tar and as the sole emulsifying and dispersing agent from 0.06 to 1.5 parts by weight based on the weight of said coal tar of a mixed sodium hydroxide-dodecylamine salt of an interpolymer of from about 95% to 99.99% by weight of acrylic acid and from 0.01% to 5% by weight of a polyallyl sucrose the weight ratio of said hydroxide to said amine being from about 0.0125:1 to 0.221 respectively said dispersion having a pH of from about 5 .2 to 7.

7. A stable tar-in-water dispersion comprising at least 35 parts by weight of water, up to 65 parts by weight of homogeneously and finely-dispersed RT-l to 12 coal tar and as the sole emulsifying and dispersing agent from 0.06 to 1.5 parts by weight based on the weight of said coal tar of a mixed sodium hydroxide-polyethylene oxide modified dodecylamine salt of an interpolyrner of from about 95% to 99.99% by weight of acrylic acid and from 0.01% to 5% by weight of tetravinyl silane the weight ratio of said hydroxide to said amine being from about 0.0125 :1 to 0.221 respectively said dispersion having a pH of about 5.2 to 7.

8. A stable tar-in-water dispersion comprising at least 35 parts by weight of water, up to 65 parts by weight of homogeneously and finely-dispersed RT-l to 12 coal tar and as the sole emulsifying and dispersing agent from 0.06 to 1.5 parts by weight based on the weight of said coal tar of a mixed sodium hydroxide-polyethylene oxide modified dodecylamine salt of an interpolymer of from about 95% to 99.99% by weight of acrylic acid and from 0.01% to by weight of 1,8-nonadiene the weight ratio of said hydroxide to said amine being from about 0.0l 25:1 to 02:1 respectively said dispersion having a pH of about 52 to 7.

9. A stable tar-in-water dispersion comprising at least 35 parts by weight of water, up to 65 parts by weight of homogeneously and finely-dispersed RT-l to 12 coal tar and as the sole emulsifying and dispersing agent from 0.06 to 1.5 parts by weight based on the Weight of said coal tar of a mixed sodium hydroxide-polyethylene oxide modified dodecylamine salt of an interpolymer of from about 95% to 99.99% by weight of acrylic acid and from 0.01% to 5% by weight of tetraallyl silane the weight ratio of said hydroxide to said amine being from about 0.0125 :1 to 02:1 respectively said dispersion having a pH of about 5.2 to 7.

10. A stable tar-in-water dispersion comprising at least 35 parts by Weight of water, up to 65 parts by weight of homogeneously and finely-dispersed RT-l to 12 coal tar and as the sole. emulsifying and dispersing agent from 0.06 to 1.5 parts by weight based on the weight of said coal tar of a mixed sodium hydroxide-polyethylene oxide modified dodecyl amine salt of an interpolymer of from about 95% to 99.99% by weight of acrylic acid and from 0.01% to 5% by weight of tetra-allyl pentaerythrito] the Weight ratio of said hydroxide to said amine being from about 0.0125:1 to 02:1 respectively said dispersion having a pH of about 5.2 to 7.

11. The method for preparing stable tar-in-water dispersions comprising stirring in water as the sole emulsimerizable With (1) and 3) from about 0.01 to about 10% by Weight based on the total weight of monomer of an olefinic monomer having at least two polymerizable olefinic groups in each molecule, neutralizing said polymer to a pH of from about 5 to 8 with a mixture of an organic amine having at least 6 carbon atoms and being selected from the class consisting of aliphatic primary, secondary, tertiary amines, quaternary amine hydroxides and alkyl ene oxide-treated amines and an alkali metal base selected from the group consisting of alkali metal hydroxides, oxides and carbonates, the weight ratio of said base to said amine being from about 0.012521 to 0.221 respectively and slowly adding a molten RT tar to the stirred polymer-water mixture.

12. The method of claim 11 wherein at least parts by weight of water, up to about parts by weight of coal tar and from about 0.05 to 2 parts by weight of the poly-v mer based on the weight of said coal tar are employed.

References Cited in the file of this patent 

1. A STABLE TAR-IN-WATER DISPERSION COMPRISING AT LEAST 35 PARTS BY WEIGHT OF WATER, UP TO ABOUT 65 PARTS BY WEIGHT OF HOMOGENEOUSLY AND FINELY DISPERSED COAL TAR AND AS THE SOLE EMULSIFYING AND DISPERSING AGENT FROM 0.05 TO ABOUT 2 PARTS BY WEIGHT BASED ON 100 PARTS OF SAID COAL TAR OF A MIXED ALKALI METAL BASE-ORGANIC AMINE SALT OF A SYNTHETIC LIGHTLY CROSS-LINKED WATER-SWELLABLE CARBOXYL CONTAINING POLYMER THE WEIGHT RATIO OF THE ALKALI METAL BASE TO ORGANIC AMINE BEING FROM ABOUT 0.0125:1 TO ABOUT 0.2:1 SAID ALKALI METAL BASE BEING SELECTED FROM THE GROUP CONSISTING OF ALKALI METAL HYDROXIDES, OXIDES AND CARBONATES, SAID ORGANIC AMINE HAVING AT LEAST 6 CARBON ATOMS AND BEING SELECTED FROM THE CLASS CONSISTING OF ALIPHATIC PRIMARY, SECONDARY, TERTIARY AMINES, QUATERNARY AMINE HYDROXIDES AND ALKYLENE OXIDETREATED AMINES AND SAID LIGHTLY CROSS-LINKED CARBOXYL CONTAINING POLYMER BEING AN INTER-POLYMER OF (1) AT LEAST 20% BY WEIGHT OF AN ALPHA, BETA-OLEFINICALLY UNSATURATED CARBOXYLIC ACID, (2) UP TO ABOUT 80% BY WEIGHT OF ANOTHER MONOOLEFINIC MONOMER COPOLYMERIZABLE WITH (1) AND (3) FROM ABOUT 0.01 TO ABOUT 10% BY WEIGHT BASED ON THE TOTAL WEIGHT OF MONOMER OF AN OLEFINIC MONOMER HAVING AT LEAST TWO POLYMERIZABLE OLEFINIC GROUPS IN EACH MOLECULE SAID DISPERSION HAVING A PH OF FROM ABOUT 5 TO ABOUT
 8. 